I had an amazing case with a motherboard tray that would slide out. It meant you could connect everything up, put the cpu cooler on and put the tray back in the case...so much easier.
I don't know why they don't do this more.
I also miss my gameport sidewinder force feedback steering wheel and pedals.
The thing I most regret was selling my amiga with everything (games, joystick, magazines) in order to fund a 28k modem. The magazines I really miss giving away.